The present invention relates to an inflatable air bag system useful in the deployment of an inflatable air bag cushion over a portion of a vehicle during a collision event. More particularly, the invention relates to an inflatable air bag system including an air bag cushion deployable from a confined storage position over a region of extended length wherein such deployment is carried out by the introduction of a gaseous inflation medium from a pressurized storage receptacle which extends at least partially along the region to be covered by the air bag cushion. The discharge of the inflation medium into the air bag cushion may be either substantially instantaneous or may be prolonged over an extended period so as to realize desired inflation characteristics.
It is well known in motor vehicles to provide air bag cushions for protecting a vehicle occupant during a collision event. Such air bag cushions are typically in fluid communication with chemically activated gas generating inflators which expel inflation gas into the air bag cushion upon the occurrence of predetermined vehicle conditions such as deceleration exceeding a certain level. The inflation gas which is released by such chemically activated inflators is typically expelled at an elevated temperature which may require the air bag cushion to incorporate heat shielding elements and/or gas defusers to protect against any damage which might be caused to the air bag cushion by impingement of such high temperature gases. It is further known to operate such reaction based inflators in combination with reservoirs of pressurized stored gas in so-called xe2x80x9chybrid inflatorsxe2x80x9d to increase available inflation volume while lowering the overall temperature of the inflation gas.
It is also known to provide air bag systems which include inflatable restraint cushions deployable over extended portions of a vehicle interior from storage positions extending adjacent to the roof along the roof rail portion of the vehicle frame such that the inflatable restraint cushion extends downwardly in substantially curtain-like fashion between the occupant to be protected and the side portions of the vehicle adjacent to such occupant. Such coverage is intended to provide a degree of cushioning restraint for the occupant during a side impact or extended roll over collision event. Inflation of such side curtain air bag cushions is typically achieved by means of a standard inflator packaged at a location such as the xe2x80x9cAxe2x80x9d pillar or xe2x80x9cCxe2x80x9d pillar which is remote from the storage position of the air bag cushion. Such prior systems may require the incorporation of a diffuser tube within the air bag cushion to obtain early inflation at a central portion of the air bag cushion.
Prior curtain-like air bag cushions which have been deployable from storage positions adjacent the roof of a vehicle have thus required a generally complex arrangement involving the remote generation of inflation gas and the subsequent conveyance of such inflation gas into the curtain structure through a diffusion element in order to achieve rapid and substantially uniform deployment of the air bag cushion away from its storage location. Moreover, such prior curtain-like air bag cushions have typically been inflated by relatively high temperature reaction gases which may dictate the utilization of heat shielding elements and/or diffusers to guard against heat damage to the air bag cushion. In addition, the remote placement of such inflation units may result in undesirable complexity in the mounting and storage of such inflators at positions remote from the storage location of the air bag cushion itself.
This invention provides advantages and alternatives over the prior art by providing an inflatable air bag system including an inflatable cushion element for inflated deployment over an extended surface to be covered from a storage position extending adjacent to such surface. Inflation of the cushion element is achieved by the rapid release of pressurized inflation gas from a relatively low profile gas impermeable sealed enclosure extending adjacent to the region to be covered. Due to the presence of the gas storage receptacle in the region immediately adjacent to the region to be covered by the inflatable cushion element, inflation gas may be conveyed directly into interior portions of the inflatable cushion element without the use of a diffuser element. In addition, due to the fact that the inflation gas is conveyed outwardly from the gas storage receptacle by pressure relief, rather than chemical reaction, the air bag cushion is not subjected to undue temperature increases.
According to one aspect of the present invention, an inflatable air bag system is provided including a substantially curtain-like cushion element for deployment from an elongate storage compartment in covering relation over a portion of a vehicle passenger compartment generally adjacent to an occupant to be protected. Inflation of the inflatable cushion element is achieved by the rapid release of a pressurized volume of substantially inert gas from an elongate storage receptacle disposed substantially adjacent to the region to be covered and extending at least partially along the length of the storage compartment of the cushion element.
According to another aspect of the present invention, an inflatable air bag system is provided including a substantially curtain-like cushion element for deployment downwardly from a position of storage along the roof rail of a vehicle in covering relation over a side portion of a vehicle passenger compartment generally adjacent to an occupant to be protected. Inflation of the inflatable cushion element is achieved by the rapid release of a pressurized volume of substantially inert gas from an elongate storage receptacle disposed along the roof rail of the vehicle and extending along at least a portion of the length of the passenger compartment so as to provide stiffening support to the stored cushion element along the profile of the roof rail. Release of the gas from the storage receptacle is carried out by the localized perforation of the storage receptacle.
According to another aspect of the present invention, an inflatable air bag system is provided including a substantially curtain-like cushion element for deployment downwardly from a position of storage along the roof rail of a vehicle in covering relation over a side portion of a vehicle passenger compartment generally adjacent to an occupant to be protected. Inflation of the inflatable cushion element is achieved by the rapid release of a pressurized volume of substantially inert gas from an elongate storage receptacle disposed along the roof rail of the vehicle and extending along at least a portion of the length of the passenger compartment. Release of the gas from the storage receptacle is effected by the localized perforation of the storage receptacle for substantially direct conveyance into a central portion of the cushion element at a position along the length of the passenger compartment.
According to another aspect of the present invention, an inflatable air bag system is provided including a substantially curtain-like cushion element for deployment downwardly from a position of storage along the roof rail of a vehicle in covering relation over a side portion of a vehicle passenger compartment generally adjacent to an occupant to be protected. Inflation of the inflatable cushion element is achieved by the rapid release of a pressurized volume of inflation gas from an elongate storage receptacle disposed along the roof rail of the vehicle and extending along at least a portion of the length of the passenger compartment. The storage receptacle includes a primary storage compartment and at least one secondary storage compartment that release inflation gas at different rates so as to prolong the period of gas discharge in a controlled manner.
According to one exemplary embodiment of the present invention, an inflatable air bag system is provided which includes an inflatable curtain-like cushion element for inflated deployment downwardly away from a storage position along the roof rail portion of the vehicle frame to provide coverage over a side portion of the vehicle interior rearward of the xe2x80x9cAxe2x80x9d pillar of the vehicle frame in side relation to an occupant within the interior of the vehicle. The cushion element is inflated by the rapid introduction of a substantially inert gas such as helium from an elongate gas storage receptacle extending at least partially along the roof rail portion of the vehicle frame. The gas storage receptacle serves as a profiling and stiffening support member for the cushion element in the storage position extending along the roof rail. The inflation gas is discharged directly into an interior portion of the cushion element so as to promote rapid expansion and deployment of the cushion element over centralized regions of the surface to be covered. The rapid expulsion of the inflation gas from the gas storage receptacle may be achieved by the controlled puncture of the gas storage receptacle at a location corresponding to the desired point of inflation gas introduction into the cushion element.